(CNN)The idea of vetting Muslims didn't start with Donald Trump, or even with the 9/11 attacks. It goes back to this country's earliest days.

Well before the Pilgrims landed in "New Jerusalem," Columbus had set sail on a mission to find riches to retake "old" Jerusalem from the Ottoman Empire. Centuries later, when colonists sought to unite the States, Anti-Federalists railed against the Constitution. Nothing in the new document, they fumed, would prevent a Muslim from becoming president.

The first Muslims to arrive en masse came in chains. Scholars estimate that some 10,000 to 20,000 slaves from West Africa were Muslims. A few were granted preferential treatment because they could read and write Arabic and looked "whiter" than other slaves. They were paraded across the country like prized pets until they started advocating for their emancipation.

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This series explores the lives of Muslims in the age of ISIS and Islamophobia.

"Such is the bloodthirsty, tyrannical Mahometan negro, who is now travelling himself and suite, up and down through the free states in pomp, with the President's passport in his pocket," snarled one Southern newspaper about a Muslim slave freed by President John Adams.

Within a few generations, African Islam was extinguished, snuffed out by plantation owners who converted their slaves to Christianity.

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In the 1880s, Muslim immigrants from the tottering Ottoman Empire began to arrive. Before they were allowed into the country, they were required to sign oaths swearing that they owed no loyalty to the empire's Sultan. Even then, most were not allowed to become citizens.

The United States was committed to the idea that its future depended on its identity as a white Christian nation, said Kambiz GhaneaBassiri, author of "A History of Islam in America."

"The presumption has been that all Muslims are considered suspect until proven otherwise."

During his campaign, Trump continued that presumption, saying that "Islam hates us," accusing Muslims of refusing to report terrorists in their midst and arguing that "there's no way to tell" whether Syrian refugees "have love or hate in their heart."

Still, Trump and his administration insist that his new executive order is not a "Muslim ban," even though it halts immigration from seven predominantly Muslim countries for three months, bars Syrian refugees (most of whom are Muslim) indefinitely and gives preference to non-Muslim refugees.

Instead of a religious test, Trump calls his plan "extreme vetting." "This is not about religion," he said in a statement. "This is about terror and keeping our country safe."

Like Trump's executive order, American laws have rarely barred Muslims by name, which would be unconstitutional. But to many courts and customs officials, the intent of the laws were clear. So were their effects.

The Naturalization Act of 1790 allowed only "free white persons" to become US citizens. After the Civil War, "persons of African descent" were added to the list. By the classifications of the era, most Muslim immigrants were neither. The Supreme Court's suspicions of Islam were evident in a decision about foreign courts in 1891, in which one justice lamented "the intense hostility of the people of the Moslem faith to all other sects."

Laws passed in 1917 and 1924 made it even harder for Asian and Middle Eastern Muslims to immigrate and become citizens.

In 1942, a Michigan judge denied a Yemeni man's case for citizenship. Apart from the man's dark skin, he ruled, it was "well-known" that Arabs "are part of the Mohammedan world ... and a wide gulf separates their culture from the predominantly Christian peoples of Europe."

Those Christian peoples, of course, trace their religious roots to the Middle East -- the very region the judge deemed irremediably "Mohammedan." By that logic, Muslim immigrants argued, Jesus himself could not be an American citizen. The judge was not persuaded.

Even Muslims born and raised in the United States were considered suspicious, especially if they were not white. As thousands of blacks embraced new, Islam-inspired movements such as the Moorish Science Temple and the Nation of Islam in the mid-20th century, the FBI kept a nervous watch.

"Though it did not produce peer-reviewed scholarship," writes scholar Edward Curtis, "the FBI was by far the most prolific student of Muslim groups in the first half of the 20th century."

The FBI's report on the Nation of Islam fretted that black Muslims demonstrate "fearless and outspoken anti-white, anti-Christian attitudes. ... As long as racial inequity continues, the militant and arrogant manner of cult members remains a potential threat of violent action."

In 1965, the United States eased immigration restrictions, opening the door to nearly 3 million immigrants, many of them economic refugees from countries with sizable Muslim populations.

Pew says that number will climb past 8 million by 2050, when Muslims will become the second-largest religious group in the United States, a surge driven by immigration, large families and the relative youth of American Muslims (their median age in 2010 was 23). Even in 2050, though, Muslims will only make up 2% of the US population.

After the September 11, 2001, terrorist attacks, the Bush administration enacted a "special registration" program that disproportionately targeted Arabs and Muslims and was a point of contention between rights groups and the federal government for nearly a decade.

Sources close to the Trump administration say it's possible he could revive the program, known as NSEERS, setting up Muslims in the United States for another round of "extreme vetting."